A touch screen has been used in many cases for a liquid crystal display window of electronic equipment such as mobile information terminals such as PDAs and handy terminals, office automation equipment such as copiers and facsimiles, smartphones, mobile phones, portable game consoles, electronic dictionaries, car navigation systems, small PCs, digital cameras, video cameras, and portable MDs (PMDs). Among some types of touch screens, a capacitive touch screen is highly popular. This is because the capacitive touch screen has an excellent multi-touch function of enlarging and reducing an image by tapping, flicking, pinching a screen with a fingertip, an excellent visibility, and an excellent durability.
An example of the capacitive touch screen is disclosed in Patent Literature 1. In Patent Literature 1, a touch screen is realized as a capacitive film sensor 30, and this film sensor 30 is adhered to a back surface of a cover panel 12 placed in a liquid crystal display window of the electronic equipment described above, functioning as a dielectric, and having a light transmitting property.
In a third embodiment of Patent Literature 1, the film sensor 30 includes a base film 32, a first electrode portion 40 formed on a surface 32a of the base film 32, another base film 33 laminated on the other side of the base film 32, and a second electrode portion 45 formed on a surface 33a of the another base film 33.